Plasma Volume Estimate

Enter height, weight, sex, and hematocrit to calculate total blood volume and derive plasma volume through the (1 − hematocrit) relationship.

Use the fractional hematocrit (e.g., 42% for 0.42).

Total blood volume

4985 mL

Plasma volume

2891 mL

Plasma volume

2.89 L

Plasma volume estimation helps with therapeutic plasma exchange, volume status assessment, and pharmacokinetic dosing. Adjust for pregnancy, obesity, or extreme hematocrit deviations when applying clinically.

How to Use This Calculator

1

Enter anthropometric data

Use measured height and weight. Consider ideal or adjusted body weight in extreme obesity to avoid overestimation.

2

Provide current hematocrit

Use hematocrit from the same blood draw. Plasma volume is blood volume multiplied by (1 − Hct).

3

Apply clinically

Use plasma volume to guide therapeutic plasma exchange, estimate hypervolemia, or tailor drug dosing requiring intravascular volume.

Formula

Nadler blood volume (male) = [0.3669 × (Height(m))³ + 0.03219 × Weight(kg) + 0.6041] × 1000

Nadler blood volume (female) = [0.3561 × (Height(m))³ + 0.03308 × Weight(kg) + 0.1833] × 1000

Plasma volume = Blood volume × (1 − Hematocrit)

Full Description

Plasma volume represents the intravascular fluid compartment excluding red blood cells. Clinicians leverage plasma volume estimates for plasmapheresis dosing, assessment of intravascular depletion/excess, and pharmacokinetic modeling for protein-bound medications. Adjust estimations for pregnancy, obesity, and acute hemodilution or hemoconcentration, and validate with clinical findings when precision is critical.

Frequently Asked Questions

Does anemia affect accuracy?

Yes. Hemodilution lowers hematocrit, increasing calculated plasma volume. Interpret results alongside clinical assessment.

Can I use this for pediatric patients?

Nadler’s formula is validated in adults. Pediatric plasma volume estimates require age-specific formulas.

What if weight is unstable?

Use dry weight when available (e.g., dialysis patients) to avoid fluid overload skewing blood volume estimates.

How is this used in plasmapheresis?

Plasma exchange prescriptions commonly remove 1–1.5× plasma volume per session based on these estimates.